The first ever scientific study of the cost of eradicating invasive animal and plant species has come up with the staggering estimate of £1.7 billion a year in England, Scotland and Wales.

The research was initiated by the devolved Scottish Government and suggested that the costs of eradicating the invaders was £1.3 billion to the English economy, £251 million to the Scottish economy and £133 million to the Welsh economy.

These were the results of in-depth studies involving just five species - Asian long-horned beetle, carpet sea squirt, water primrose, grey squirrel and coypu – but there are many other plants and animals introduced by man which have been attacking native wildlife for decades.

These include mink and signal crayfish, Japanese knotweed and poisonous giant hogweed.

Roseanna Cunningham, Scottish Government Minister for Environment and Climate Change commented:"We all know about the serious threat to our native wildlife from invasive non-native species, and this report confirms the huge cost to businesses and individuals in Great Britain every year.

"A better understanding of the negative impacts of invasive non-native species can help us raise awareness to help prevent introductions in the first place and to better respond to problems.”

Compared to many other nations, Britain has very lax border controls on the import of foreign animals and plants. In America, any visitor found carrying fruit or seeds by airport security staff is refused entry. American citizens caught can be sent to jail.

The Scottish report emphasises the importance on taking early action to eradicate newly invasive species before they take hold here – but in many cases, it is far too late because they are now considered to be native residents.